Lubricant containing hydrogenated liquid polymer oils



LUBRICANT CONTAINING KilYDl'tGGENATED LIQUID POLYMER HEELS David W.Young, Westfield, and Deimer L. @ottle, Highland Park, N. J., assignorsto Esso Research and Engineering Company, a corporation of Delaware NoDrawing. Original application May 27, 1954, Serial No. 432,936. Dividedand this application November 1, 1954, Serial No. 466,204

3 Claims. (Cl. 25246.6}

This application relates to a method of improving liquid polymer oilsand more particularly relates to the preparation of new class ofaddition agents from such oils.

It is known to prepare oily polymers by the polymerization of aconjugated diolefin such as butadiene or the copolymerization of such adiolefin with a vinyl aromatic such as styrene. These polymeric oilshave been found to be excellent drying oils and therefore useful inpreparing varnishes, paints and enamels.

However, the films prepared from these oils have been found prone tocheck or fracture badly on exterior exposure and finally to flake awayfrom the supporting surface. Furthermore, baked films prepared fromthese oils, while superior to most synthetic drying oils, still are notas satisfactory as those obtained from most natural drying oils.

According to the present invention such polymer oils are subjected tohydrogenation to improve the weather resistance and adhesion of thebaked films and other properties of the oil and to obtain productssuitable as plasticizers for natural and synthetic rubber, polyethylene,asphalt and wax and as addition agents for lubricating oils and thelike.

The polymer oil which is to be subjected to hydrogenation, according tothis invention, is prepared by copolymerizing about 50 to 100 parts ofbutadiene-l,3 and about 50 to parts of styrene at 25 to 105 C. in thepresence of 1.2 to 8 parts of finely divided sodium, per 100 parts ofmonomers, as the catalyst and of about 50 to 500 parts of an inerthydrocarbon diluent boiling between 0 and 250 C., preferably between 20and 200 C. in either a batch or continuous process.

The above choice of monomers is quite specific as halogen-containingmonomers such as chloroprene or chlorinated styrene are not suited forpolymerization in the presence of sodium. Higher homologues of butadienei. e. piperylene, isoprene, and dimethylbutadiene are suitable for thepurpose of the present invention. The replacement of styrene by its ringalkylated homologues, such as para-methyl styrene, meta-methyl styrene,dimethyl styrene and the corresponding ethyl substituted homologues isthe only variation of monomers permissible herein, however, styrene isthe most practical from the economic standpoint. Alpha methyl styrene isunsuitable because it is too unreactive toward sodium.

Materials used as diluents in the polymerization should be liquid at thepolymerization temperature, that is, they should boil between 20 and 250C., although more volatile materials boiling as low as 15 C. may also beused, providing that the polymerization pressure is increasedcorrespondingly. Preferred diluents are essentially aliphatichydrocarbons such as naphtha (boiling range about 90 to 120 C.), orstraight run mineral spirits such as Varsol (boiling range about 150 to200 C.), but butane, pentane, benzene, toluene, xylene, cyclo- 2,798,853Patented July 9, 1957 ice hexane, butenes, pentenes or similar inerthydrocarbons are also usable, individually or in admixture with eachother. In general, the aromatic solvents are not so desirable as thealiphatic ones because of the toxicity of the former. The hydrocarbondiluents are used in amounts ranging from 50 to 300 parts by weight perparts of monomers.

An important feature of the process involves the use of a substantialamount of certain C4 to Ca aliphatic ethers as codiluents or modifiersalong with the hydrocarbon diluent described above. A particularlyoutstanding promoter for the batch process has been found in dioxane-1,4whose presence in the feed aids in the production of a colorless productof desirable viscosity and good drying properties, and promotes thereaction sutficiently to give 100% conversion at 50 C.,. in a period ofabout 6 to 12 hours. Similarly favorable results were also obtained withdiethyl ether (CzH5)zO, as Well as with methylal, ethylal, methylacetal, and tertiary butyl methyl ether. In the batch process, diethylether is usable, although the initial induction period tends at times tobe somewhat long. However, diethyl ether is the preferred ether in acontinuous process as the difficulty in starting up the reaction occursonly at the beginning of the polymerization which runs for a long periodof time in contrast to batching runs which have to be started upfrequently. Diethyl ether is less subject to undesirable side reactionswith metallic sodium, and it is a more vigorous promoter than dioxane.However, dioxane is usable also, but not preferred. Other ethers usefulto a still lesser extent are diethyl acetal, vinyl i-sobutyl ether,dihydropyrane and ethylal, all of which have a favorable etfect onimproving the color of the product.

In contrast to the preferred ethers named earlier herein, the fourethers just named have a moderate retarding effect on tr epolymerization rate. Finally, all cyclic ethers having an O--CO- groupin a ring structure, such as dioxane-l,3, dioxolane, paraldehyde andglycol ethylidene diacetal, inhibit the polymerization rate soexcessively that their use is impractical. Dimethyl ether also does notserve the desired purpose, both as regards reaction rate and productquality. Thus the cyclic ethers must have the oxygen atoms separated byat least two carbon atoms. 1 The ether promoter is used in amountsranging from about 1 to 100 parts, preferably 5 to 50 parts by weightper 100 parts of monomers. In selecting the ether codiluent it isespecially desirable in many cases to select an ether having a boilingpoint of at least 10 C. below the lower limit of the boiling range ofthe hydrocarbon diluent, and thus, when using a mineral spirits having aboiling range of 150 C. to 200 C., ether co-diluents boiling betweenabout 25 and C., are preferred for the reason that their separation fromthe hydrocarbon diluent in the polymerized reaction mixture is greatlyfacilitated by virtue of the stated difference in boiling points. If thepolymer is recovered in about 100% purity, the ether may convenientlyboil in the range of the hydrocarbon diluent since both may be recycledtogether in making up the fresh feed to the reactor.

It is also advantageous to use about 10 to 50%, preferably 10 to 30weight percent (based on sodium) of an alcohol in the polymerizationrecipe. Suitable alcohols include isopropanol, isobutanol, isopentanol,secondary butanol, and tertiary butanol. The coarser the catalystdispersion, the more essential it is to have a sufiicient amount ofalcohol promoter present.

The reaction time and induction period vary depending on the degree ofcatalyst dispersion, reaction temperau ture, purity of feed materialsand sequence of monomer addition.

The catalyst is usually fed to the reactor as a slurry of metalparticles dispersed in 2 to 200 parts by weight of a hydrocarbon liquid,which may or may not be the same as the reaction diluent. Agitation ofthe reaction mixture during synthesis increases the efliciency of thecatalyst.

Destruction of catalyst at the end of the reaction is effectivelyaccomplished by adding to the reaction mixture a moderate excess of ananhydrous C1 to C5 fatty acid which is soluble in the hydrocarbonmixture, e. g. formic, acetic or pentanoic, or with sulfuric acid asdescribed in copending application Serial Number 396,324, filed December4, 1953. After destruction of the catalyst the crude polymerizationproduct containing the salts, excess acid and other impurities isneutralised with ammonia, and the neutralized product is finallyfiltered preferably with a filter aid such as silica gel, clay, charcoalor its equivalent. Separation can also be accomplished by centrifuging,if desired. Other ways of destroying the catalyst may be used, such asby. adding alcohol, or inorganic acids.

Since, the resulting polymer solution is usually too dilute for mostpractical use as a varnish or enamel base, it is advantageous to distilloff some of the volatile hydrocarbon solvent until a product containingnot less than 40% to 70% non-volatile matter is obtained, thenon-volatile matter being the polymeric drying oil. Where even morehighly concentrated products are dea sired it is possible to raise theconcentration of the polymeric drying oil to as much as 99% or greaternon-volatile matter by still more extensive distillation or stripping;the use of a stripping gas, such as methane or a mixture of lighthydrocarbons, is advantageous where highly concentrated drying oils aredesired. Alternatively, one may use a low boiling diluent such asbutane, a pentane, or a low boiling naphtha in the synthesis step andthus simplify the eventual removal of the diluent from the polymericproduct.

The product of the present invention is usually a solution of polymericdrying oil in a suitable hydrocarbon solvent such as solvent naphtha ormineral spirits and is, depending on the amount and type of ether used,a clear, colorless to light yellow varnish composition, the polymercontent of which has a viscosity of about 0.15 to 22 poises at 50% N. V.M. and preferably 0.15 to 3.0 poises at 50% N. V. M.

If desired, the product viscosity can be readily increased within orabove the limits given above by heatbodying the polymer, preferably in50 to 75% concentration, in the absence of air at temperatures between200 and 300 C., e. g. at 220 to 260 C. The clear varnish composition canbe brushed, poured or sprayed and gives good clear films on drying inair or baking, especially when conventional driers such as naphthenatesor octoates of cobalt, lead or manganese are added thereto. Excellentfilm can be prepared by baking, even in the absence of driers.

Furthermore, when the drying oil compositions of the present inventionare intended for use in pigmented enamels, their gloss and wetting powercan be further improved by reacting them with a small amount of a polarcompound such as maleic anhydride, acrylonitrile, thioglycollic acid orother equivalent materials described in copending applications Ser. Nos.102,703, filed July 16, 1949 (now issued as Patent No. 2,652,342) and106,487, filed July 23, 1949, now Patent No. 3,683,162.

Lead driers can be used also, but, unlike in the case of natural dryingoil varnishes, are not necessary here. This, of course, is a decidedadvantage in some cases in view of the toxicity of the lead driers.

Another important advantage of the invention is that the present dryingoils can be used as a varnish without the addition of any extraneouspolymer or resin 4 thereto. This further distinguishes the products ofthe invention from prior art drying oils, notably the natural oils suchas linseed, which require the addition of rosin, ester gum or a phenolicresin thereto when a varnish is desired.

Now, according to the present invention, a polymer oil made as describedabove is subjected to hydrogenation to reduce its color and iodinenumber and effect other improvements. This hydrogenation may be carriedout either by treating the polymer before stripping out part or all ofthe diluent hydrocarbons or the stripped polymer may be redissolved in asuitable inert solvent to facilitate hydrogenation in the liquid phase.

The hydrogenation may be carried out under any desired hydrogenatingconditions, such as contacting the polymer solution with gaseoushydrogen under a pressure of about to 5000 p. s. i. g. preferably about500 to 3000 p. s. i. g., at a temperature range from about 200 to 500F., preferably about 300 to 450 F. for a time ranging from a few minutesto several days, but preferably about 10 to 30 hours. In order to avoidgel formation by crosslinking, it is necessary that the hydrogenation becarried out gradually as instantaneous hydrogenation results in theproduction of an insoluble product. It is preferred to use ahydrogenation catalyst, which may be any of the known types such asnickel, reduced nickel, platinum, or various metal sulfides, etc.,either alone or supported on a suitable carrier of great porosity orsurface area, e. g. charcoal, silica gel, etc. In patch operation, theamount of catalyst should generally be about 5 to 50% by weight, basedon the weight of polymer subjected to hydrogenation. In continuoushydrogenation, the feed rate of the polymer or the polymer solutionthrough the catalyst bed should be about 0.1 to 5, preferably 0.3 to 1.0v./v./hr.

After the hydrogenation is completed, i. e. carried out to the desiredpressure drop or reduction in iodine number, and improvement in colororother characteristics, the solution may be subjected to flashing ordistillation to remove the solvent and any other volatile materials, andif desired, the hydrogenated polymer may be stored, shipped, orotherwise marketed for use while still dissolved in the hydrogenationsolvent. In such a case, however, it should be subjected to filtering orother purification treatment to remove the catalyst.

These hydrogenated polymers have iodine numbers between 1 and and havevalue as varnish extenders, for cobodying with other resins and/ordrying oils, for floor tile compositions, printing inks, paints, asbonding agents for plywood, as plasticizers for natural rubber andsynthetic rubbers, such as butyl rubber, GR-S, GR-N, asphalt,polyethylene and wax, and as addition agents for lubricating oils andthe like. The proportions may vary between 1 and 30% of the hydrogenatedoil.

The hydrogenated copolymers as described above have beenfound to havelubricating oil and wax modifying characteristics which make themparticularly desirable for blending with various lubricating oil basestocks and waxes. It has been found that either natural occurringmineral oils or synthetic lubricating oils may be improved by theaddition of minor but improving proportions of the hydrogenated polymersdescribed above.

It has also been found that the residual unsaturation present in thehydrogenated polymeric materials make it possible to further react thehydrogenated polymeric material with agents such as sulfides ofphosphorus, chlorinated aliphatic compounds, acylating agents,sulfonating agents and the like. These reaction products also enhancethe desirable characteristics of lubricating oils and waxes with whichthey are blended.

The objects, advantages and details of the invention will be betterunderstood from the following experimental data which are given for thesake of illustration, but without intending that the invention belimited specifically thereby.

greases EXAMPLE I Y An oily copolymer of butadiene and styrene wasprepared according to the following recipe:

Butadiene parts by weight 80 Styrene do 20 Varsol do"-.. 10 Naphtha do190 Dioxane dn 30 Sodium do 1.5 Isopropanol do 0.3 Temperature C 40Complete conversion was obtained in 10 hours. The catalyst was destroyedand removed. The product was finished to 90% N. V. M. as described aboveand had a viscosity of 1.0 poise at 50% N. V. M.

EXAMPLE II EXAMPLE HI 83 g. of the copolymer prepared as described inExample I above was placed in a 1.9 liter bomb and a catalytic amount ofRaney nickel catalyst was added along with about 200 g. heptane. Thebomb was pressurized with hydrogen to a pressure of between about 1850and 2400 lbs. The temperature was raised to 190 C. and increased after afew hours to 270 C. After from 16 to 21 hours of reaction time, acolorless, stable hydrogenated polymer was obtained that had a molecularweight of about 8,000 Staudinger and an iodine number of about 6. Theiodine number of the starting material was 313. 5, This'hydrogenatedpolymer wasblended with a highly refined paratfinic distillate having aviscosity at 210 F. of 4-5 SUS and a viscosity index of 113. The blendcontaining 1 /2% of the hydrogenated polymer had a viscosity at 210 F.of 51.7. SUS and a viscosity index of 127. A blend containing 2 /2% ofthe hydrogenated copolymer had a viscosity at 210 F. of56.3 SUS and aviscosity index of 131.5.

EXAMPLE IV The copolymer of Example I above was hydrogenated PercentHydrogenated M. PL, Viscosity ASIM Pene- Copolyrner F. at 250 F.,tration, 77

cs. F.

As another concept of the instantinvention it is contemplated that thehydrogenated copolymer be subjected to chemical treatment byphosphorizing alone, or in conjunction with sulfurizing, the chemicaltreatment either being carried out to a greater or more severe extent inorder to impart extreme pressure lubricating, or antioxidant, or othervaluable properties to the copolymer.

This chemical treatment may be carried out in a number of differentways. For instance, for phosphorizing alone, the treating agent maycomprise either elemental phosphorus or a phosphorizing compound such asa phosphorus oxyhalide, e. g., POCls, POBrs, etc., phosphorus pentoxideP205, etc., or mixtures thereof. A preferred class of treating agents isone comprising phosphorus and also an element of the sulfur family whichincludes sulfur, selenium and tellurium. Such an agent, which may beconsidered as of the P.Y type, where Y is a member of the sulfur family,may consist of a simple mixture of for instance, phosphorus or sulfur,or a compound of these two elements, e. g., P2S5, P483, P2S3, P4S7,P2Se5, etc., or mixtures of such compounds with either or both of theindividual elements. I Another preferred class of treating agents may beconsidered of the P.Y.X. type, where Y is the same as above, and Xrepresents halogen. Examples of such agents include PSCla, PSBra,PSFBrz, PSFzBr and P2S3Br4. Such agents may readily be made by reactingthe appropriate phosphorus halide with hydrogen sulfide; for instance,PSBI's is made from PBrs and H2S. A still .further type of treatingagent is one of the P.O.Y. type, where Y has the same meaning as above,as in the compound P4O6S4. Mixtures of any of the above types oftreating agents may be used.

Another modification of the invention comprises first sulfurizing thehydrogenated copolymer and then phosphorizing it. In such a case, thesulfurizing may be effected by heating the copolymer alone or togetherwith a suitable solvent, e. g., carbon disuliide, with elemental sulfur,or by reacting with a sulfurizing compound of the Y.X type, where Y andX have the same meanings as above, as in the case of sulfur monochlorideS2012, sulfur dichloride SClz, sulfur monobromide SzBrz, etc. Thesubsequent phosphorizing treatment may then be carried out by treatingwith elemental phosphorus or a phosphorizing compound such as POCls,POBrs, PCls, P285, P205 etc., or mixtures thereof.

A still further modification of the invention comprises firstsulfonating the copolymer as by treatment with fuming sulfuric acid of 5to 20% fuming concentration, at relatively mild temperatures, or bycommercial, concentrated sulfuric acid, or even weaker acid, at highertemperatures, and in higher proportion to the amount of copolymertreated. The resultant sulfonated copolymer is then phosphorized in thesame manner as described above for treatment to follow a sulfurizingstep.

In canrying out the above described chemical treatment, the amount oftreating agent will, of course, vary, depending upon the types ofcopolymer and treating agent used, and the extent of chemicalmodification. desired, but normally will range from about 0.1 to 5% byweight of treating iagent based on the weight of the copolymer treated.The temperature of reaction will, of course, also vary inversely withthe strength and amount of treating agent, and extent of modificationdesired, but normally will range from about room temperature to about250 C. or so, generally about to 200 C.

The reaction is also preferably carried out in the presence of an inertliquid serving as solvent and/ or a diluent such as paraffinichydrocarbons e. g., petroleum ether or refine-d higher boiling fractionssuch as naphtha, kerosene, gas oil or lubricating oil.

After the treatment with a phosphorus sulfide or other treating agentdescribed above, the reaction mixture should be filtered and distilled,or otherwise treated if necessary to remove any volatile solvent, and ifdesired, the product may be neutralized or partially neutralized with abasic metal neutralizing agent such as one of the.follow, ing metals infinely-divided form: calcium, barium, mags nesiurn, aluminum, tin,nickel, cobalt, sodium, potassium, etc., or oxides, hydroxides,carbonates or other suitable compounds of suchv metals. After suchneutralization, the finai product should be filtered to remove unreactedneutralizing agent.

Another important modification of the invention is carrying out theabove described chemical treatment of a copolymer, in the presence of afatty oil such as one or more of the various vegetable oils, e. g.,soybean oil, linseed oil, cottonseed oil, or animal oils, e. g.,. lardoil, etc, or fish oils, e. g., whale oil, sperm oil, etc. When thusphosphorizing the copolymer in the presence of a fatty oil: such asthose described above, it is believed that not only are the copolymerand fatty oil each separately phosphorized', but also it is believedthat there is some co-reaction between these materials so that eithersome condensation of the fiatty oil with the copolymer takes placethroughthe medium. of'the phosphorizing treatment, either alone or inconjunction with the sulfurizing treatment, or in any event, theresultant product is considered to be more stable and more effectivethan if the materials Were separately treated and then mixed togetheralone or added to a lubricating oil'.

A preferred method of carrying out the invention is to carry out thechemical, e. g., phosphorizing, treatment of the copolymer whiledissolved in a portion of a lubricating oil, so as to make a concentrateof the treated prod uct, which can then readily be diluted with furtheramounts of lubricating oil, to make a lubricant of the desired finalcomposition. In such a case, the concentrate may advantageously containfrom. 1 to 50%, preferably about 5 to 30%, of the treated copolymer, andthe finished blend should ordinarily contain an amount of treatedpolymer ranging from about .01% to about preferably about 0.1-. to 5.0%

An example of the phospho-sulturization of these copolymers is givenbelow.

EXAMPLE V The hydrogenated copolymer prepared as described in ExampleIII above was dissolved in 5% concentration in a parafinic minerallubricating oil having a viscosity of 52 SUS at 210 F. and a viscosityindex of 100. 5 g. of P2S5'Was then added to 100 g. of the blend and themixture heated to 180 C. for 60 minutes. The solution was cooled to roomtemperature and filtered through a layer of Hiflo filter aid on paper.The clear solution was analyzed. and found tocontain 2.61 weight percentsulfur and 0.783 weight percent phosphorus. This blend, when tested onthe standard Almen machine, anextreme pressure testing machine, carriedthe full load of weights with gradual loading. The same base oil, thisbase oil containing 5% concentration of the hydrogenated copolymer whichwas not treated with P285, or the base oil alone treated with P255 asabove would not carry all the weights in this test.

It is also Within the concept of this invention to react the.hydrogenated copolymer of this invention with a dihalogenated or otherpolyhalogenated organic compound such as a dihalogenated hydrocarboncompound having the general formula RXz where R represents a hydrocarbongroup and X represents halogen, attached to R through aliphatic carbonlinkages. Examples of such reagents include ethylene dichloride,propylene dichloride and higher alkylene dichloride, as well ascorresponding bromide derivatives, or mixtures of two or more differentalkylene halide compounds. Other polyhalogenated hydrocarbons such astrichloro trifluoro propylene, dimer and trimer of trichlorotrifluoropropylene,.difluoro ethane, CC14,. trifluoroalkyl alkyl ethers, carbontetrafluoride (Freon l4), l-chl'oro-l, l-di fluoro ethane (Freon 142),chloropentafluoro ethane (Freon 115') and the like may be: used- Highermolecular weight reagents for reacting withthe hydrogenated copolymermay be prepared for instance by halogenating parafiin wax or otherparaffinic hydrocarbons such as cetane, octadecane, triisobutylene,polymethyl pentadiene, polypropylene, polybutene, polyethylene, butylrubber, etc. It will be understood of course that when such hydrocarbonsare halogenated, for example chlorinated, the resulting product willgenerally consist of a mixture of monochlor, dichlor and/or trichlorderivatives, depending essentially upon the total amount of chlorinecombined into the hydrocarbon product. For the purposes of the presentinvention, the amount of incorporated halogen (or mixed halogen)" shouldusually range from about l030%, preferably from about 10' to 15 or 20%.Very good results have been obtained with chlorinated paraflin waxcontaining from 12 to 14% of chlorine. Such a product containing forinstance 12% of chlorine probably contains monochlorinated wax moleculesand dichlorinated WlElX molecules in approximately the same proportion.If the total product contains above about 14% of chlorine, however, theproportion of dichlorin'ated molecules probably slightly exceeds theproportion of monochlor molecules. Good results have been obtained witha wax that contained 2% fluorine and 14% chlorine. Also interestingresults have been obtained on a wax that contained a trace of Br, 1% ofF and 14% chlorine.

The condensation of the halogenated hydrocarbons with the hydrogenatedcopolymer should preferably be carried out in the presence of aFriedel-Crafts condensation catalyst such as aluminum chloride, boronfluoride, A1BI3, AlBrzCl, AlCl'zBr, AlzB rsCI, (AlzBrsCLAlOBr),(AlClzOH.AlCl) etc. The reaction is also preferably carried out in thepresence of a solvent, which may be either inert under the conditions ofthe reaction, such as tetrachlorethane, carbon tetrachloride, etc., orit may be an aromatic type of solvent, such as benzene, toluene, or apetroleum (aromatic naphtha, which is capable of condensing With one ofthe two halogen atoms on the dihalo hydrocarbons used as reagents. Arefined heavy petroleum naphtha may be used, which consists chiefly ofsaturated hydrocarbons and a small amount of aromatics.

The following is an example of this concept of the invention. I

EXAMPLE VI The hydrogenated copolymer prepared as described in ExampleIII (15' g. was reacted with a chlorinated waxcontaining 11% chlorine(4.8 g.) 3% of aluminum chloride was used as a catalyst and the solventfor the reaction was kerosene g.). The temperature of the reaction wasmaintained at between 115 and C. When the reaction was completed, theproduct was washed with water and stripped to remove the solvent.

This material was blended with a naphthenic distillate having aviscosity at 210 F. of about 56 SUS, an ASTM pour point of +20 and aviscosity index of 103. A blend containing 0.5% of the alkylatedhydrogenated copolymer had an ASTM pour point of 5 F. and a viscosityindex of 106.

EXAMPLE VII Three samples of butyl rubber (copolymer of 97% isobutyleneand 3% isoprene) were'cured for 60 minutes at 287 F. according to thefollowing recipes:

Captax-Z-mercapto-benzothiazole Sulfur '2 '2' '2 Mineral Oil 10Unhydrogenated polymer of Example I 10 Hydrogenated polymer of Exam leIII. Butyl rubber hang...

Sample 1- cured easily while sample 2 blistered badly,

Q while sample 3 did not blister.

The cured products had the following properties: it

Sample 1 2 3 Tensile/sq. in 2, 500 40 2, 400 Elongation, Percent 680 650Modulus at 100 F 980 O 1, 000 Mooney viscosity:

EXAMPLE VIII it Various amounts of the hydrogenated polymer of ExampleIII were added to a 160-180 F. oxidized Columbian asphalt. The followingresults were obtained.

Physical properties of hydrogenated copolymer oil in N0'rE.--Copolyrnerused had iodine number of 6, and at 1.5% in EMO #1 base oil it gave avis. of 51.7 SSU and a V. I. of 127.

The asphalt used in the above example may be substituted bysteam-reduced asphalts, oxidized asphalts, natural asphalts, coal tarasphalts, CCl4-treated asphalts and PzOa-treated asphalts. The asphaltsmay have other resins and polymers present as well as some oil, wax,etc. Anti-oxidants, fillers, etc. may be present. A light solvent orwater may be present to make a paint, etc.

As another embodiment of the instant invention, it is contemplated toacylate the hydrogenated copolymer described above with an acylatingagent.

The acylating agent to be used in accordance with this invention forreacting with a copolymer of the abovedescribed class may be selectedfrom a wide Variety of materials having the general formula R(COX)nwhere R is a hydrocarbon group, X is a halogen and n is an integer from1 to 3, preferably 1 to 2. The acylating agent most generally preferredis derived from a fatty acid, and when the product is to be employed asan additive for a lubricating oil, the hydrocarbon radical shouldcomprise 5 to 30 carbon atoms acyl chlorides having from to carbon atomsin an alkyl group being especially desirable. Suitable acyl halides maybe derived, for example, from palmitic acid, stearic acid, phenylstearic acid, adipic acid, sebacic acid, coconut oil acids, commercialfat acids, mutton tallow fatty acids, arachidic acids and the like.Where solubility of the product in oil is not required, the acylatingagent may be a short chain acyl chloride, such as acetyl chloride.Naphthenyl halides, derived from petroleum naphthenic acids, may also beused, as well as acid halides, derived from cyclohexane carboxylic acid,phthalic acid and the like. Slightly unsaturated acid halides may alsobe used as oleyl chloride. For making a plasticizer for syntheticrubber, lower acylating agents may be used, e. g. acetyl chloride,propionyl chloride, butyryl chloride, succinyl chloride, etc.

In carrying out the acylation reaction, it is desirable to employ from 1to 10 parts by weight of acylating agent to 1 part of the copolymer, 1to 5 parts of the acylating agent being preferred when a long chainacylating agent, of the order of 10 carbon atoms or more, is employed.

10 The amount of acylating agent which it is desirable to use in aparticular case will depend partly on the proportion of the combinedcyclic constituent in the copolymer, as well as upon the molecularweight of the acylating agent, and upon the purpose for which theproduct is to be used.

The acylation is preferably carried out in the presence of aFriedel-Crafts type catalyst, such as aluminum chloride, zinc chloride,stannic chloride, boron fluoride, anhydrous hydrogen fluoride and thelike. The amount of this catalyst required is generally from 0.5 to 3parts per 1 part of copolymer. The catalyst is preferably added in smallportions during the course of the reaction.

The reaction is preferably carried out in the presence of a suitableinert solvent, including highly halogenated hydrocarbons, such ascarbontetrachloride, te'trachlorethane, o-dichlorbenzene and the like,as well as hydrocarbon solvents such as refined aliphatic hydrocarbonsof the type of heavy naphtha, kerosene and the like. The amount ofsolvent may range from about 1 to 20 volumes or so per volume of thereactants present.

The temperature required for the acylating reaction depends partly uponthe reactivity of the particular acylating agent used and partly uponthe amount of solvent and the proportion of combined cyclic constituentin the copolymer, but normally will range from about to about 300 F.,preferably from to 250 F.

T he time required for the completion of the reaction may vary from /2to 10 hours, depending upon the nature of the reactants and thetemperature of the reaction, but the reaction will normally be completedwithin 1 to 5 hours. The completion of the reaction is evidenced by thesubstantial cessation of hydrogen chloride evolution. When the reactionis completed, the mixture may be cooled, and if very viscous, is thenpreferably diluted with additional solvent; and then the residualcatalyst is destroyed by adding water, alcohol, aqueous hydrochloricacid, aqueous caustic soda, etc. The resulting catalyst sludge is thenwithdrawn and the solvent extract containing the desired acylatedcopolymer may be Washed repeatedly, preferably until the final washWater shows no test for acid with litmus paper. The acylated copolymermay, if desired, be used in solution in the solvent if thus recovered,or the solvent may be removed by distillation or other suitable means soas to recover the acylated copolymer per se. If it is desired to use theacylated copolymer eventually in solution in a mineral lubricating oil,a small amount of such oil may be added to the volatile oil solutionbefore evaporation of the volatile solvent so that after suchevaporation the residue will consist of a mineral lubricating oilconcentrate of the acylated copolymers, containing, for example, about15% to 50% of such acylated copolymer. If the copolymer precipitates outof the solvent before or upon addition of the catalyst destroying orhydrolyzing agent, the copolymer may be washed by mixing, milling orkneading with water until freed of catalyst and then dried by hot mixingor vacuum drying, etc.

The copolymers as described above may also be sulfonated to obtain manydesirable derivatives. The sulfonation is accomplished by use of atreating agent selected from the group consisting of acid-reactingcompounds of an element capable of forming polybasic inorganic acids,.and halogen-, organic-, and other substituted derivatives thereof,including acids of sulfur, phosphorus, arsenic, boron and the like, suchas sulfuric acid, nitrosylsulfuric acid, fuming sulfuric acid, sulfurtrioxide, phosphoric acid or sulfur pentoxy dichloride, sulfurylthiocyanate (SO2(SCN)2) phosphorus pentoxide, a reagent made bydissolving phosphorus pentoxide in strong sulfuric acid, phosphorushalides such as phosphorus oxychloride or -oxybromide, or-oxybromchloride, and phosphorus trichloride, either alone or with acatalyst such as AlCls, Mg powder or using instead of'the copolymer aGrignard reagent RMgX made by halogenating the copolymer and reactingwith Mg powder to make phosphonic and phos- 1 1 phinic derivatives, orother acids such as chlorsulfonic acid, fluorsulfonic acid, and weakeracids such as sulfurous acid, sulfur dioxide, phosphorous acid, etc, maybe used provided more stringent reaction conditions are-used than arerequired with the stronger acids.

Organic-substituted acids include alkyl, aryl', alkar' yl, aralkyl,cycloalkyl, alkox-y, etc. derivatives of these various acids where suchan organic group replaces a hydroriyl group, oxygen, ora hydr oxylhydrogen atom as in meth ane, sulfonic acid, amyl phosphoric acid,dibutyl phosphoric acid, isopropyl sulfuric acid, etc.

A wide variety of different types of products can be obtained, not onlyby the use of various amounts of acid, and various concentrations ofacid (as by the use of sulfuric acid of 65%, 95% or 120% strength), butalso by starting with copolymers having the desired combinathan ofphysicalandchemical properties which may be adjusted both by control ofthe proportions of styrene and diolefin.

The reaction may be carried out in the presence of an inert solvent suchas refined petroleum naphtha or kerosene, etc. or chlorinated solventssuch as ethylene dichloride, tetrachlorethane, CCLi, nitromethane, whiteoils, etc. The reaction temperature should be about 50 C. to 130 C., or0 to 150 0., depending upon the strength of acid, amount of solvent,etc. The reaction may be carried out under vacuum or at atmosphericpressure or at various higher pressures such as 2, 10, etc. atmospheresor higher.

This application is a division of application Serial No. 432,936 filedMay 27, 1954.

The nature of the present invention having been thus fully set forth andspecific examples of the same given, what is claimed as new and usefuland desired to be secured by Letters 'Patent is:

l. A mineral lubricating oil having added thereto, a

tained by cop'olymerizing to parts by weight of butadiene-1,3 and 50 to0 parts by weight of styrene inthe presence of finely divided solium,said hydrogenated polymer having an iodine number below (ASTM);

2. An improved lubricating oil composition which comprises a minerallubricating oil base stock containing a minor but pour point depressingproportion of the re action product of a chlorinated aliphatic compoundwith. a hydrogenated polymer prepared by hydrogenating the oily polymerobtained by copolymerizing 50 to 100 parts by weight of butadiene-1,3and 50 to 0 parts by weight of styrene in the presence of finely dividedsodium, said hydrogenated polymer having an ASTM iodine number below150.

3. A lubricating oil composition which comprises a mineral lubricatingoil base stock containing a minor but extreme pressure resistanceimproving amount of the reaction product of a sulfide of phosphorus witha hydrogenated polymer prepared by hydrogenating the oily polymerobtained by copolymerizing 50 to 100 parts by weight of butadiene-1,3and 50 to 0 parts by weight of styrene in the presence of finely dividedsodium, said hydrogenated polymer having an ASTM iodine number below150.

References Cited in the file of this patent UNITED STATES PATENTS2,472,495 Sparks June 7, 1949 2,595,819 Smyers May 6, 1952' 2,615,004Jasper Oct. 21, 1952 2,686,759 Giammaria Aug. 17, 1954

3. A LUBRICATING OIL COMPOSITION WHICH COMPRISES A MINERAL LUBRICATINGOIL BASE STOCK CONTAINING A MINOR BUT EXTREME PRESSURE RESISTANCEIMPROVING AMOUNT OF THE REACTION PRODUCT OF A SULFIDE OF PHOSPHORUS WITHA HYDROGENATED POLYMER PREPARED BY HYDROGENATING THE OILY POLYMEROBTAINED BY COPOLYMERIZING 50 TO 100 PARTS BY WEIGHT OFF BUTADIENE-1,3AND 50 TO 0 PARTS BY WEIGHT OF STYRENE IN THE PRESENCE OF FINELY DIVIDEDSODIUM, SAID HYDROGENATED POLYMER HAVING AN ASTM IODINE NUMBER BELOW150.